Was betrifft es? Warum ist das wichtig?

A study design is an applied strategy with the aim to answer a given study question. The main and most frequently used design categories include:

 

  • Randomized Controlled Studies (RCS): are considered the “gold standard” for assessing the effectiveness of an intervention. Participants are randomly assigned to either an intervention or a control group. Only the intervention group receives the intervention under investigation. The control group receives a reference treatment or a placebo (e.g. a treatment with no active ingredient). A causal relationship is tested by comparing the intervention with the control group

 

  • Observational studies: are study designs where a research question is answered purely through observation. Data is collected from participants, but no attempts are made to actively intervene or affect the outcome (e.g. no treatment given). Observational studies are either prospective (e.g. data is collected prospectively) or retrospective (e.g. historical data is used for analysis)

Was muss ich befolgen?

As a SP-INV, make yourself familiar with these main study categories. Consult a statistician to discuss the most appropriate study design (within these two categories) needed to answer your study question.

Observational studies are valuable for exploring associations, identifying risk factors, and generating hypotheses. See examples of observational studies under More!

Mehr

Example of observational studies

 

These studies can be either:

  • Prospective: where data is collected during study conduct. Example: a group of pregnant women are followed during pregnancy while monitoring their dietary habits and their haemoglobin levels. The aim is to examine the relationship between nutrition and haemoglobin levels during pregnancy

 

  • Retrospective: where historical data is used (e.g. patient files) of patients with a particular disease. Thus, an association between historically implemented treatments or methods (e.g. surgery procedures) and a disease status can be investigated. Example: A study analyses electronic health records from diabetic cohort patients, to investigate the association between statin use and cardiovascular outcome. The study compares the incidence of cardiovascular events between statin users and non-users over a five-year period (i.e. a cohort is a group of people with shared characteristics, such as in this example diabetes)

Wo kann ich Hilfe anfordern?

Your local CTU can support you with experienced staff regarding this topic

References

ICH Topic E9 statistical Principles for Clinical Trials – see in particular

  • 3.1 Design configuration
Abkürzungen
  • CTU – Clinical Trials Unit
  • ICH – International Council for Harmonisation
  • RCS – Randomized Controlled Study (better known as RCT – Randomized Controlled Trial)
  • SP-INV – Sponsor Investigator
Basic ↦ Statistics ↦ Study Design ↦ Definition
Study
Basic

Provides some background knowledge and basic definitions

Basic Monitoring
Basic Drug or Device
Concept

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Drug or Device
Development

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Drug or Device
Set-Up

Starts with ethics and regulatory approval

Ends after successful study initiation

Set-Up Ethics and Laws
Set-Up Quality and Risk
Set-Up Drug or Device
Conduct

Starts with participant recruitment

Ends after the last participant has completed the last study visit

Conduct Drug or Device
Completion

Starts with last study visit completed

Ends after study publication and archiving

Completion Statistics
Completion Drug or Device
Current Path (click to copy): Basic ↦ Statistics ↦ Study Design ↦ Definition

Please note: the Easy-GCS tool is currently under construction.